security_dac: check if virSecurityDACGetIds returns negative
security_dac: check if virSecurityDACGetIds returns negative

Use the customary check '< 0' instead of checking for non-zero.

No functional change.

fabianfreyer/libvirt,zippy2/libvirt,datto/libvirt,rlaager/libvirt,taget/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,crobinso/libvirt,jardasgit/libvirt,jfehlig/libvirt,rlaager/libvirt,eskultety/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,taget/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,libvirt/libvirt,olafhering/libvirt,libvirt/libvirt,eskultety/libvirt,crobinso/libvirt,datto/libvirt,andreabolognani/libvirt,eskultety/libvirt,jfehlig/libvirt,taget/libvirt,eskultety/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,datto/libvirt,olafhering/libvirt,andreabolognani/libvirt,jardasgit/libvirt,zippy2/libvirt,libvirt/libvirt,nertpinx/libvirt,andreabolognani/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,rlaager/libvirt,rlaager/libvirt,fabianfreyer/libvirt,eskultety/libvirt,rlaager/libvirt,taget/libvirt,olafhering/libvirt,libvirt/libvirt,crobinso/libvirt,jfehlig/libvirt,datto/libvirt,nertpinx/libvirt,olafhering/libvirt,zippy2/libvirt,crobinso/libvirt,datto/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,zippy2/libvirt,jfehlig/libvirt,taget/libvirt,nertpinx/libvirt,jardasgit/libvirt